Plug and socket devices of this type are provided, for example, in power lines which serve for the connection of heavy-current load, for example, of strong electric motors in workshops or the like. These devices are known for voltages of up to 500 volts. The coupling can be effected in these cases in such a way that it is secured by means of a kind of bayonet catch. Such a coupling is limited in its application particularly if the coupling is to be intended for connecting lines carrying higher voltages. The couplings then have a comparatively large size and heavy weight and, therefore, are difficult to manipulate.